Therapeutic compositions containing



United States Patent Ofiice 4,4-DISUBSTITUTED S-PYRAZDLIDINONES AND This invention is concerned with new pharmacologically active compounds. More particularly the invention relates to 4-substituted 3-pyrazolidinones of the general formula:

R CO-N-Rll RI CH2-'N-Ra wherein R represents an alkyl, aryl or aralkyl radical, R represents an alkyl radical having at least 2 carbon atoms, or an aryl or aralkyl radical and R and R represent hydrogen or alkyl, aryl or aralkyl radicals; and a process for preparing the same. The above compounds are active as antiphlogistics and on the central nervous system.

The process for the preparation of the new 3-pyrazolidinones essentially consists in the following steps: (1) opening of the lactone ring of a-substituted ,B-propionolactones with hydracids, giving the corresponding a-substituted B-halopropionic acids, (2) conversion of the carboxyl group into the corresponding alkyl ester .or acyl chloride and (3) reaction of the a-substituted ,8-haloacid esters or chlorides with hydrazine or its derivatives.

The reaction scheme is as follows:

R 00 R COOH \C/ \O \C/ 4 z Rl \CH2X (I) I) R OOY R CO-N-R Ri \CH2X Ri CH2NR3 (III) (IV) wherein R, R R R have the above significance, X is halogen and Y represents chlorine or an alkoxy group.

The synthesis of the compounds of formula II is carried out by reacting an a,ot-diSllbStill11t6d B-propionolactone with the selected hydracid, preferably in an inert organic solvent. For practical purposes, the preparation can, for example, be carried out by dissolving in an inert organic solvent, such as glacial acetic acid,-the a t-disobstituted fl-hydroxypropionic acid lactone, adding the mixture to a solution of the hydracid in the same solvent or in a solvent miscible with the same, allowing the mixture to stand at room temperature and then heating the same to complete reaction.

From the reaction mixture the compound is then isolated by usual methods, for example by evaporating the reaction solvent to dryness and working up the residue. a,oc-diS1IbStitllted B-halopropionic acids are useful intermediates not only for the preparation of pyrazolidinones, which are the primary object of the present application, but also for the production of new penicillins from 6- aminopenicillanic acid.

These latter penicillins forming the subject of our copending application S.N. 184,539, filed simultaneously herewith, show a high degree of activity against .penicillinase producing strains of microorganisms and possess a considerable degree of stability to acids; thus allowing 3,166,568 Patented Jan. 19, 1965 ral therapy with penicillins also in infectious diseases due to penicillin-resistantstrains.

The conversion into the corresponding acid halides or esters is carried out as usual, for example, by treating the acid either with thionyl chloride, if the acid chloride is desired, or with an alcohol in the presence of a catalyst if the ester is to be prepared.

The a,a-disubstituted ,B-halopropionic acid halide or ester is then reacted with the selected hydrazine, if desired, in excess, in the presence or not of an organic solvent and in the presence of a proton acceptor which may be the same hydrazine if sufficiently basic. Depending upon the nature of the used hydrazine, which can be unsubstituted, monoor 1,2-disubstituted, there are obtained disubstituted, trisubstituted or tetrasubstituted 3- pyrazolidinones. These latter tetrasubstituted 3-pyrazolidinones can also be obtained starting from dior trisubstituted 3-pyrazolidinone and introducing the desired substituent at the nitrogen atom by conventional alkylation methods.

The following non-limiting examples illustrate the invention.

Example 1.4-phenyl-4-n-butyl 3-pyraz0lidin0ne A stream of gaseous anhydrous HBr is bubbled into ;100 ml. of glacial acetic acid at room temperature,

completing the saturation at 0-5 C. Then 20.4 g. of a-phenyl-u-n-butyl-B-propiolactone is added dropwise under stirring and the temperature is allowed to reach l()20 C. The mixture is kept at room temperature 3ft)! two hours and then heated at 80 C. for 2 hours.

I The distilled residue gives in good yield a-phenyl-a-nbutyl-fl-bromopropionic acid, M.P. 100102 C., which is converted into the corresponding chloride.

To 12 g. of crude u-phenyl-a-n-butyl-,8-bromopropionyl chloride in ml. of anhydrous ethyl alcohol, 5.5 g.

of triethylamine are added and the mixture is allowed to stand at room temperature overnight. Then it is heated for a short time, cooled, filtered and the, solvent removed in vacuo. The residue is taken up with diethyl ether, washed with dilute HCl, then with water, dried over :Na SO filtered and the solvent removed to give ethyl filtered and the solvent distilled to give 4-phenyl-4-butyl- 3 pyrazolidinone; B'.P. 170175 C./0.2 mm. Hg.

Example 2.4-phenyl-4-benzyZ-3-pyfaz0lidinone Two hundred and fifty millilitres of glacial acetic acid are saturated with gaseous HBr and 59.5 g. of a-phe'nyla-benzyl-fi-propiolactone are added dropwise under stirring. The mixture is allowed to stand 2 hours at room temperature and then heated at C. for 2 hours. acetic acid is evaporated in vacuo and the oily residue is taken up with H 0 and ethyl ether. The ether solution, separated from the aqueous phase, is washed with small amounts of water to neutrality to Congo red, dried over Na SO filtered and the solvent evaporated. The residue recrystallized from ligroin gives a-phenyl-abenzyl-B-bromopropionic acid; M.P. l72 C. A'

mixture of 32 g. of a-phenyl-u-benzyl-B-bromopropionic acid and 23.8 g. of thionyl chloride is heated till the evolution of gas subsides, ie for about 2 hours. The excess reactant is then evaporated in vacuo and the oily The 3,166,568 3 4i residue so obtained is taken up with 100 ml. of absolute Example 20.1-methyl-4-phenyl-4-ethyI-S-pyragolidinone ethyl alcohol. Then 11.2 g. of triethylamine are added and the mixture is allowed to stand overnight at room Three and eight tenths grams of Sodium are dissolved temperature. The mixture is refluxed for 10 minutes, in 250 f absolute eihyi alcohol and 9 0f cooled, the precipitated triethylamine hydrochloride is 5 P Y Y -Py and 21 of dimeihyi filtered and the alcohol is distilled off in vacuo. The Phflie are added dropwise keeping the temperature between residue is taken up with ether, the solution is washed i0 and The mixture is refluxed 1 hour, the fi t i h dil t Hcl d h i h water, d i d over solvent is evaporated and the residue treated with warm :[\Ia S() and filtered The ether is removed in vacuo ethyl ether. The inorganic salts are filtered OE and the and ethyl -phnyl- -benzyl-fl-bromopropionate is b. SOilItlOIl iS washed water and dried over C8504. 1- tained in good yield; B.P. 158160 c./0.4 mm. Hg. y -p y y -py is obtained.

The obtained bromoester (8.8 g.) is refluxed 18 hours Q/O-Z with 2.5 g. of anhydrous hydrazine. The excess hydrazine is removed and the residue, recrystallized from Example j j ligroin, gives 4-phenyl-4-benzyl-3-pyrazolidinone; M.P. pyrazolzdmone Examples Into a solution of 1.6 g. of sodium hydroxide in 30 ml. of water 2.8 g. of l-phenyl-4,4-diethyl-3-pyrazolidinone According to the procedure described in the precedare dissolved; Then -83 g. of dimethyl sulphate are ing examples the following 3-pyrazolidinones were preadfied dfopwlse uhder Shmhg at room temperature for 30 pared; minutes. The mixture is heated for 1 hour at 50 C., cooled, extracted wth ethyl ether, and the oil obtained by O evaporation of the solvent is distilled in vacuo. l-phenyl- R R M.P., 0. RP.

R1 R2 3 2-methyl-4,4-diethyl-3-pyrazol1d1none 1S obtalned, B.P. CZHS 02m H H 120%? M02 ISO-160 C./0.2 mm. Hg, M.P. 60-61" C. (from isomm. Hg. propyl ether). nC3H nC3H7 H H res-170250100 11- H 12135 6 1 Example 22.-1-phanyl-Z-methyl-4-phenyl-4-ethyl-3- CH3..-... 1 125-127 pyrazolidinone C2H5 I-r H 105-107 n-C3H l-l H 17 180 C./ .4 A mixture of 5.26 g. of 1-phenyl-4-phenyl-4-ethyl-3- Hm 16mm pyrazolidinone, 6.9 g. of potassium hydroxide and 7.1 g.

of methyl iodide in 50 ml. of acetone is refluxed for 8 hours. The inorganic salt is filtered off and the solvent is Example 10-1A'dipheny[-4-]?utyl'3'pyl'azolidinone evaporated. The residue is dissolved in ethyl ether, the A mixture f 20 f wphenypwbutYLGbromoProether solution is washed with water, dried and the solvent pionic acid prepared substantially as described hereinevflpofaied- The fesldhe 15 Purified y distillation 111 before and 30 ml. of thionyl chloride is refluxed for 3 Vaeuo- The Pieduet disiiis at c/O-2 hours. The excess S001 is removed in vacuo. The obtained 21.7 g. of acyl chloride are dissolved in 71 ml. Examples 23-33 of anhydf 011$ ether, ahda sehliieh 0f of p y Substantially as described in the preceding examples the hydrazine, gof triethylamine and i following 1,2,4,4-tetrasubstituted 3-pyrazolidinones were hydrous ether is added dropwise. The mixture is stirred prepared;

for 30 minutes at 0 C. and refluxed for 1 hour. After cooling, the triethylamine salt so formed is filtered off, the ether solution is washed with dilute HCl, water, a R R1 R2 R3 M'Ror BL sodium bicarbonate solution and again with water. The

solution is dried over CaSO the solvent is evaporated 16H. CJLsmmHg and the residue is crystallized from petroleum ether. 160l65:C./0.5rnm. Hg. 1,4 diphenyl-4-butyl-3-pyrazolidinone melting at 8385 3580 g5 C. 1s obtained in good yield. 116 o 220230 C./0.8 mm. Hg. 160 C./0.6 mm. Hg. ISO- C./0.4 mm. Hg. 176 C./0.4 mm. Hg. 2l0220 C./0.G mm. Hg. 180 C./0.2 mm. Hg.

Examples 11-18 According to the procedure described in Example 10 the following derivatives were prepared:

Example 34.1,2-diphenyl-4,4-dielhyl-3-pyraz0lidin0ne In 100 ml. of anhydrous pyridine 18.4 g. of hydrazo- 123-124o 60 benzene are dissolved under an atmosphere of inert gas,

72-74 0. then 22.4 g. of a,a-diethyl-fi-bromopropionyl chloride are added at 0 C.

1434500 The mixture is heated at 100 C. for 2 hours to complete reaction, then it is cooled, filtered and evaporated in 65 vacuo. The residue is taken up with ethyl ether, treated 11-0411 180190 C./0.2mn1. Hg.

Example 19.1-methyl-4,4-diethyl-3-pyraz0lidin0ne with an ether Solution of HC] and filtered To a solution of 0.5 g. of sodium in 30 ml. of ethyl The ether Solution iS Washed With 2 dilute NaOH alcohol 2.84 g. of 4,4-diethyl-3-pyrazolidinone are added and again With 2 then it is dried Over z -z- The with stirring until the solution is complete. Then 2.77 g. y residue Obtained after evaporation of the Solvent is of dimethyl sulphate are added dropwise Th mixture 70 distilled at 170180 C./0.2 mm. Hg. The distillate i8 is refluxed for 1 hour, the solvent is evaporated and the ehfemaieglaphed 011 alumina, then diluted with Petroleum residue extracted with ether to remove some by-products. ether, Petroleum ether-benzene and finally with Then it is dissolved in anhydrous acetone, filtered, and benzene. The third fraction (in benzene) is formed by the remaining oil is distilled; 1-methyl-4,4-diethyl-3-pyrpractically pure 1,2-diphenyl-4,4-diethyl-B-pyrazolidinone, azolidinone is obtained; B.P. 140150 C./0.4 mm. Hg. 75 M.P. 99100 C.

Examples 35-36 the following compounds were prepared: I

R R1 R2 R2 M.P. or B.P.

OBI-I5 CH3.-. C5H5 C0115... 190195 C./0.2mm. 06m c6115.- C5115... 0 11 144146 o.

We claim:

1. A compound of the formula wherein R indicates a member of the class consisting of lower alkyl, phenyl and phenyl-lower alkyl; and R is a 1 member of the class consisting of lower alkyl having at least 2 carbon atoms, phenyl, and phenyl-lower alkyl.

2. 4-phenyl-4-butyl-3-pyrazolidinone.

3. 4 phenyl-4-benzyl-3-pyrazo1idinone.

4. 4,4-diethyl-3-pyrazolidinone. I

References Cited by the Examiner UNITED STATES PATENTS 2,212,056 2,289,367 7/42 Kendall 2603 10 .Substantially as described in the preceding examples A 8/40 ITinker et al. 260 515 May 25249.6

OTHER REFERENCES Zaugg et al.: Jour. American Chem. Soc., volume 72,

, pages 3004-7 (1950).

Nerdel et al.,' Chem. Berichte, volume 92, pages 1329 Burger, Medicinal Chemistry, 2nd Ed., pp. 341-44, N.Y., Intel-science, 1 960.

Conant et al., The Chemistry of Organic Compounds, 1

3rd Ed., p. 240, N.Y., MacMillan, 1947.

Nicolaus .et al., Helvetica Chimica Acta, vol. 44 pp. 2059-79 (Sept. 1, 1961).,

Royals, Advanced Organic Chemistry, pp. 605 and 61011, Englewood Clifis, PrenticHall, 1954.

IRVING MARCUS, Primary Examifiera NICHOLAS S. RIZZO, Examiner. 

1. A COMPOUND OF THE FORMULA 